Recent gains in broadband access has fueled the increasing use of video (tele)conferencing. Video conferencing enables participants at various geographical locations to “meet” at a “virtual” conference that is facilitated via high-speed communication networks and corresponding video conferencing equipment at each conference location. For instance, basic video conferencing equipment typically includes an audio and video subsystem at each location, wherein the video subsystem generally comprises a video camera and a video display (e.g., monitor or video projector and projection screen. The video camera is used to transmit video images of local participants and visual aids to a remote location (i.e., another conference location), while the video display is used to enable participants at one location to view participants and/or visual aids from other conference locations via corresponding video signals transmitted as digital data over the high-speed communication network.
In present video conferencing systems, participants in a conference generally watch the video display to observe the remote conference participants and visual aids. At the same time, the video cameras are usually mounted on the perimeter of the video display or positioned at a fixed location in the conference rooms so they do not block the view of participants wishing to look at the video display. As a result, the conference participants rarely look directly at the video camera in their respective video conference rooms, and when they do so, they are no longer able to easily view their video display. Accordingly, the video images of the conference participants make it appear as if the participants are gazing off into space, rather than looking directly at each other. Thus, although the participants may see each other at times, they cannot achieve eye-to-eye contact. This problem is exacerbated by today's larger video monitors and projection screens, since this forces the angle between the camera direction and the conference participants' focal direction to be increased. This lack of eye contact is a significant drawback, which limits the usefulness of today's video conferencing equipment in providing a natural conversation. Furthermore, without eye-to-eye contact, the trustworthiness of meeting participants is difficult to judge.
Attempts to solve this problem have been devised, with less than adequate results. One such scheme is disclosed in U.S. Pat. No. 5,675,376 to Andersson et al., wherein a controller is employed to calculate eye contours, radius profiles, and positions from images stored in memory. Once the contours and radius profiles are generated, an eye image is “shifted” via pixel manipulation to achieve eye-to-eye contact. As one might expect, this technique produces an unnatural appearance, substantially defeating the purpose of producing the eye-to-eye contact. Furthermore, the participants heads are still heading toward directions that are away from one another.